Hydrogenated olefin sulfonate-soap combination toilet bars containingalkanolamines

ABSTRACT

THE INCLUSION OF A MINOR PORTION OF TRIALKANOLAMINES IN COMBINATION WITH SODIUM HYDDROGENATED OLEFIN SULFONATE DDETERGENT AND SOAP BARS WHICH CONTAIN MORE THAN 5% BY WEIGHT OF INORGANIC SALT PREVENTS BLOTCHING OF THE BAR SURFACES.

States Patent Office 3,738,935 HYDROGENATED OLEFIN SULFONATE-SOAPCOMBINATION TOILET BARS CONTAINING ALKANOLAMINES V Gar Lok Woo, Tiburon,Califi, assignor to Chevron Research Company, San Francisco, Calif. NoDrawing. Filed May 27, 1971, Ser. No. 147,703 Int. Cl. C11d 9/30, 9/46,17/00 U.S. Cl. 252-117 5 Claims ABSTRACT OF THE DISCLOSURE The inclusionof a minor portion of trialkanolamines in combination with sodiumhydrogenated olefin sulfonate detergent and soap bars which contain morethan 5% by weight of inorganic salt prevents blotching of the barsurfaces.

BACKGROUND OF THE INVENTION Combination soap and detergent bars whicholfer substantial advantages over bars comprised of either of thematerials alone have been disclosed in the art. For example, US. patentapplication Ser. No. 849,207 now Iat. No. 3,607,776 filed Aug. 11, 1969,discloses and claims combats comprising a certain mixture of soap and aparticular detergent active that provides the desirable feel of soapbars and the noncurd-forming character inherent in detergent bars. Thebars of the above-mentioned application consist essentially of a majorproportion of one or more water-soluble salts of fatty acids having fromabout to 20 carbon atoms and a minor proportion of C -C hydrogenatedolefin sulfonates sufficientto retain in suspension the insoluble limesoaps resultmg from use of the bar in hard water.

While these combination bars have excellent lathermg, slough loss, andfeel characteristics, it has been found that they suffer an apparentdisadvantage in that due to the inorganic salt content of the barsduring storage their surfaces develop a mottled appearance. Thisappearance results from the formation upon the surface of the bar ofvisible white blemishes, possibly crystalline in structure, whichdecrease the commercial attractiveness of the bars.

SUMMARY OF THE INVENTION It has now been found that surface blemishingmay be prevented in combination sodium hydrogenated olefin sulfonatedetergent and soap bars containing more than 5% by weight of inorganicsalts by the inclusion in the bar of a minor amount of a trialkanolamineof 3 to 9 carbon atoms. The preferred trialkanolamine istriethanolamine. It is employed in minor quantities in the bar, i.e.from about 0.5 to 10 weight percent.

DESCRIPTION OF THE INVENTION The soaps used in the compositions of thisinvention are any of the conventional soaps. These soaps arewatersoluble salts of fatty acids having from about 10 to 20, preferablyfrom 12 to 18, carbon atoms. The usual watersoluble salt is the sodiumsalt; but other salts, such as the potassium or ammonium salts, may alsobe used. The fatty acid portion of the soap is a straight-chaincarboxylic acid. These acids are usually obtained by the saponificationof fats, e.g. tallow, or of oils, e.g. coconut oil. However, suitableacids may also be obtained by the oxidation of normal paraffins. Thefatty acid salts usually found in soaps include lauric, myristic,palmitic, oleic, and stearic.

The hydrogenated olefin sulfonates which comprise one component of thebars of this invention are mixed sulfonates obtained by (1) Sulfonatingstraight chain olefins containing from 10 to 24 carbon atoms with S03,738,935 Patented June 12, 1973 (2) Neutralizing and hydrolyzing theproduct of (1),

(3) Hydrogenating from to 100 percent of the unsaturatedcarbon-to-carbon double bonds in the product of (2).

The hydrogenated olefin sulfonates are present in amounts of at leastabout 5% of the total weight of soap and hydrogenated olefin sulfonatesufiicient to retain in suspension the insoluble lime soaps resultingfrom use in hard Water.

The trialkanolamines may comprise either mixed or nonmixedcompounds-that is, the alkylol groups may be the same or different ineach molecule. For example, suitable compounds include ethanoldipropanolamine, and propanol diethanolamine, etc. As previouslymentioned, the preferred material is triethanolamine because of itscommercial availability. The alkanolamine is employed in quantities offrom 0.5 to 10% by weight of the bar and preferably from about 1.0 to 6%by Weight.

The hydrogenated olefin sulfonates are obtained by the catalytichydrogenation of olefin sulfonates. The term olefin sulfonates, as usedin the present invention, de-

7 fines the complex mixture obtained by the S0 sulfonation of straightchain olefins containing 10 to 24 carbon atoms and subsequentneutralization and hydrolysis of the sulfonation reaction product. Thiscomplex mixture contains hydroxyalkane sulfonates and alkene sulfonatesas its major components and a lesser proportion of disulfonated product.

While the general nature and the major components of the complex mixtureis known, the specific identity and the relative proportions of thevarious hydroxy sulfonate and disulfonate radicals and double bondlocations are unknown. Accordingly, a determination of the entirechemical makeup is exceedingly difficult and has not heretofore beensuccessfully accomplished. The mixture is best defined by the generalprocess used for producing it as herein described.

Optimum combar properties are exhibited by a composition obtained byhydrogenating an olefin sulfonate product which contains from about 25to by Weight alkene sulfonates, from about 25 to 65% by Weighthydroxyalkane sulfonates, and not more than 20 weight percentdisulfonates. These optimum compositions are obtained by S0,:air volumeratio of about 1:50100, and an SO :olefin mole ratio of 1.051.25 :1followed by neutralization and hydrolysis of the sulfonation reactionprodnot at temperatures of 250 C. using one equivalent of base per moleof S0 consumed in the sulfonation step.

In addition to the straight chain alpha olefins from wax cracking,suitable olefin starting materials include straight chain alpha olefinsproduced by Ziegler polymerization of ethylene, or internal straightchain olefins prepared by catalytic dehydrogenation of normal paraffins,or by chlorination-dehydrochlorination of normal paraffins. The olefinsmay contain from 10 to 24 carbon atoms, usually 13 to 22 carbon atoms,per molecule. Olefin mixtures should have an average molecular weight ofat least about 200.

The amount of S0 utilized in the sulfonation reaction may 'be varied butis usually within the range of 0.95 to 1.35 moles of S0 per mole ofolefin and, preferably, in the range of 1.05-1.25 :1. Greater formationof disulfonated products is observed at higher S0,:olefin ratios.Disulfonation may be reduced by carrying the sulfonation reaction onlyto partial conversion of the olefin-for example, by using SO :olefinratios of less than 1 and removing the unreacted olefins by a deoilingprocess. The unreacted olefins may be removed by extracting the reactionproduct with a hydrocarbon such as pentane.

In order to obtain a product of good color, the S0 employed in thesulfonation reaction is generally mixed with an inert diluent or with amodifying agent. Inert diluents which are satisfactory for this purposeinclude air, nitrogen, S dichloromethane, etc. The volume ratio of S0 todiluent is usually within the range of 1:100 to 1:1.

The reaction product from the sulfonation step may be neutralized withaqueous basic solutions containing sodium, potassium or ammoniumhydroxides, carbonates, or oxides. In the preferred method, sufficientneutralizing solution may be added to provide for neutralization of thesulfonic acids formed by sultone hydrolysis. Generally, one equivalentof base for each mole of S0 consumed in the sulfonation reaction isadded to the sulfonation reaction product. The proportion ofhydroxyalkane sulfonates to alkene sulfonates in the hydrolyzedneutralized product may be varied somewhat by the manner in whichneutralization and hydrolysis are carried out. Thus, re duced amounts ofhydroxyalkane sulfonates are obtained by carrying out the neutralizationand hydrolysis at temperatures in the range of 145200 C., while higheryields of hydroxy sulfonate are favored by carrying out theneutralization and hydrolysis at temperatures below 100 C. Suitablehydrolysis temperatures range from about 100 to 200 C.

The hydrogenated olefin sulfonates described above are very goodlime-soap dispersants. That is, compositions of soap and hydrogenatedolefin sulfonate give less insoluble curd in hard water than does thesame soap alone. Any amount of the hydrogenated olefin sulfonate isbeneficial in reducing curd formation. Thus, the amount of hydrogenatedolefin sulfonate ranges upwards from about 1%, but preferably in excessof 5%, of the total weight of soap and hydrogenated olefin sulfonate. Asthe quantity of hydrogenated olefin sulfonate in the combination bar isincreased, the amount of insoluble curd that forms when the compositionis dissolved in hard water is decreased. At soap to hydrogenated olefinsulfonate ratios less than about 85:15, no curd is formed even in watercontaining 300 ppm. of hardness. It is generally preferred that thecombars of this invention contain from to 50% (by weight based on thetwo components) of hydrogenated olefin sulfonate.

The sodium hydrogenated olefin sulfonates usually have a residual sodiumsulfate content of more than 5% by weight and if prepared for makinginto bars by bleaching with, for example, sodium hypochlorite, have anadditional salt content (usually NaCl) of from about 5 to 6% by weight.The blotching problem can be overcome by very carefully controlling thereaction conditions during the sulfonation and neutralization reactionand during bleaching so that the total inorganic salt content in themixture is less than about 4% 'by weight. However, the difliculty ofaccomplishing such controlled reaction makes such production impracticalfor commercial use.

Example 1.Preparation of sodium olefin sulfonates The reactor used forthis sulfonation consisted of a continuous falling film-type unit in theform of a vertical water-jacketed tube. Both the olefin and the SO -airmix ture were introduced at the top of the reactor and flowedconcurrently down the reactor. At the bottom, the sulfonated product wasseparated from the air stream.

The feed was a straight chain l-olefin blend produced by cracking highlyparaffinic wax and having the following composition by weight: 1%tetradecene, 27% pentadecene, 29% hexadecene, 28% heptadecene, 114%octadecene, and 1% nonadecene. This material was charged to the top ofthe above-described reactor at a rate of 306 pounds/hour. At the sametime 124.2 pounds/hour of S0 diluted with air to 3% by volumeconcentration of S0 was introduced into the top of the reactor. Thereactor was cooled with water to maintain the temperature of theefiiuent product within the range of 43-46 C. The average residence timeof the reactants in the reactor was less than two minutes.

After passing out of the reactor, the sulfonated product was mixed with612 pounds/hour of 11.2% aqueous caustic and heated to l45150 C. in atubular reactor at an average residence time of 30 minutes. This stepneutralized the sulfonic acids contained in the sulfonation reactionproduct, hydrolyzed the sultones to hydroxyalkane and alkene sulfonicacids, and neutralized these sulfonic acids. Olefin sulfonates wereproduced at the rate of 463 pounds per hour as an aqueous solutionhaving a 45% by weight solids content and a pH of 10.8.

A portion of this product was analyzed and shown to be made up of thesodium salts of alkene sulfonic acids, hydroxyalkane sulfonic acids, anddisulfonic acids. These three major components were present in a weightratio of about 50:35:15.

Example 2.Preparation of hydrogenated sodium olefin sulfonates Theapparatus for this h'ydrogenation consisted of a 1-liter Magne-Driveautoclave equipped with an accumulator, a constant pressure regulator,and a temperature recording means. The product of Example 1 was dilutedwith water to a 26% solids concentration and was filtered to remove atrace amount of insoluble material. The pH was adjusted to a value of6.5-7.5 by neutralizing the slight excess of NaOH used in theneutralization and hydrolysis step with H SO One hundred parts of 30%hydrogen peroxide was then added to 3850 parts of the filtered 26%solution in an open glass vessel. This mixture was heated to C. andstirred for one hour at this temperature, after which time no hydrogenperoxide remained. After cooling this solution to room temperature, 650g. of it were charged to the previously described autoclave along with8.5 g. of Raney nickel. The system was purged with nitrogen and thenwith hydrogen. It was then pressured with hydrogen to 50 p.s.i.g. Theautoclave was warmed to C. at which temperature hydrogen was againintroduced to bring the pressure up to 100 p.s.i.g. and then vigorousstirring commenced. The hydrogen pressure was maintained constant at 100p.s.i.g. throughout the run. After 1 /2 hours of stirring at thistemperature and pressure, and at which time there was no additionalhydrogen uptake, the solution was cooled to about 70 C., filtered, andthen allowed to cool. After cooling, the final product was drum dried.

Example 3.Preparation of combars 1130 g. of commercial raw soap (amixture of coconut soap and tallow soap in a 20/80 weight ratio)containing about 7-10% water, 450 g. of the product of Example 2, 0.25%titanium dioxide, and a trace amount of a dye were added and mixed well.The resulting soap-detergent mixture was milled on a conventionalmilling apparatus and enough water was added during this millingoperation to permit the composition to be milled into ribbons. Thecomposition was then extruded and formed into bars using a conventionalsoap bar mold. The bars formed in this way were about 2% inches by 1%inches by inch in size. They were stored for one week at ambienttemperature and humidity. At the end of this time the bars weighed 26-27grams and contained 5.6% water.

Other bars were prepared in essentially the same way as before but witha 60:40 ratio of soap and hydrogenated olefin sulfonate. Both types ofbars were tested for handwashing by a panel and were found to haveexcellent soaptype feel, to form good lather, and to remove body soilsatisfactorily.

Example 4.Combination soap-hydrogenated olefin sulfonate toilet barscontaining alkanolamines Bars were prepared as in Example 3 employing30% by weight of sodium hydrogenated olefin sulfonate in combinationwith 70% of the same soap containing 1.5% by weight (relative to thesoap content) of triple pressed stearic acid as a superfatting agent and7% water. The bars were stored at a temperature of 40 F. for a periodTABLE portion of C1044 hydrogenated olefin sulfonates sufficient toretain in suspension the insoluble lime soaps resulting from use of thesoap and detergent bars in hard water, and from 0.5 to 10% by weightrelative to the weight of the bars to inhibit blotching of the finishedbars of a trialkanolamine of 3 to 9 carbon atoms, wherein said barscontain at least 5% by weight of sodium sulfate relative to thehydrogenated olefin sulfonates.

2. The bars of claim 1 wherein the trialkanolamine is triethanolamine.

Efieet of additives upon the storage Percent Soap Additive 40 F. storagetest Na HAOS Type Percent Storage Degree of Type Percent time blotching70 Severe 100 A None 70 Sodium linear alkylbenzene sulfonate 6 Severe.70 Triethenolamine 6 None. 70 C10 and C fatty alcohol.... 6 Severe. 70Sodium leuryl alcohol sulfate 6 Do. 70 Sodium hydrogenated eocoanutmonoglycende sulfate"... 6 Do. 70 Garbowax 4000 6 Do.

Note that the triethanolamine completely eliminated the blotching whilethe use of the various other additives has no effect upon the problem.

Tests showed that the addition of as low as 1% of triethanolamine tobars having spotting or blotching problems eliminated the problem.

Combination bars prepared in the same manner but using hydrogenatedolefin sulfonate which was prepared in such a manner that the barcontained less than 4% by weight of inorganic salt showed no blotching.

While the character of this invention has been described in detail withnumerous examples, this has been done by way of illustration only andwithout limitation of the invention. It will be apparent to thoseskilled in the art that modifications and variations of the illustrativeexamples may be made in the practice of the invention within the scopeof the following claims.

I claim:

1. Soap and detergent bars consisting essentially of a major portion ofone or more Water-soluble soaps of fatty acids having from about 10 tocarbon atoms, a minor References Cited UNITED STATES PATENTS 3/1972Sweeney et a1. 252|536 LEON D. ROSDOL, Primary Examiner E. L. ROLLINS,Assistant Examiner US. Cl. X.R.

PO-1O5O UNHED STATES PATENT @FFECE (5/ to W H @E'HFEQATE @F EQREQ'MNPatent No. 3, 73,8 9 35 I Dated June 12 1973 Inventor(s) Gar Lok Woo Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 6, following line 32, insert the following claims:

6. The bars of Claim 1 in which the hydrogenated olefin sulfonatescontain from 13 to 22 carbon atoms.

7 The bars of Claim 1 in which the hydrogenated olefin sulfonates arederived from alpha olefin sulfonatesa Column 1, line 9, "5 Claims shouldread 7 Claims --4.

Signed and sealed this 7th day of May 3.97Mc

(SEAL) Attest:

EDV-IM'LD l MFLE'P 3UJR,JRO Co I' IARSZIALIL DANN Attesting OfficerCommissioner of Patents

